In U.S. Pat. No. 4,192,620, there is described a ring binder comprising a sheet of material arranged to be bent so as to form a front panel and a rear panel joined by a spine and three binder strips. Each binder strip extends from the rear panel at a position adjacent the spine and is provided with a head at its free end. Each binder strip is associated with an aperture formed in the spine. When binding sheet articles, the head of each binder strip is passed through its associated aperture and secured in position. This binder suffers from the disadvantage that, as the front and rear panels are opened and closed, the position from which each binder strip extends from the rear panel and the associated aperture move relative to each other thereby creating stresses at the anchor point between the strip and the rear panel.